Speed-varying gearing



June 19, 1945. A 'L OLDl-lELD 2,378,577

SPEED VARYING GEARINGv Filed July 12, 1943 5 Sheets-Sheet 2 mmf/(KIWA INVENTOR. if hor/ful,

5 Sheets-Sh-eet 5 June 19, 1.945. oLDFlELD SPEED VARYING GEARING Filed July 12, 1943 n .11.4 W1 E Num.

Patented June 19, 1945 SPEED-VARYING GEARING Lee Oldfield, Indianapolis, Ind., assignor to Marmon-Herrington Company, Inc., Indianapolis, Ind., a corporation of Indiana Application July 12, 1943, Serial No. 494,299

2 Claims.

The object of my invention is to provide a speed change gearing' of the epicyclic type having'the capacity of four forward and one reverse speeds.

The accompanying drawings illustrate embodiments of my invention:

Fig. 1 is an axial section of an embodiment of my invention wherein driving torque is selectively applied to the sun gears through the medium of' a iluid coupling comprising two runners in series with the impeller; n

Fig. 2 a section, on a reduced scale, on line 2-2 of Fig. 1;

Fig. 3 a section of a modied form of vspeedtorque sensitive connectionbetween the output shaft and the carrier of the planet gear;

Fig. 4 av fragmentary axial section of the' construction shown in Fig. 3; and

Fig. 5 an axial section of another embodiment of my invention.

Referring rst to Figs. 1 and 2, II) indicates the impeller element of a uid coupling receiving power from a suitable source. Associated in series with impeller IlLin a wellfknown manner to form a fluid coupling, are two runners which,

(Cl. I4-189.5)

axis of the sun gears arid are carried by arms 36 projecting from ange 36 carried bythe output I shaft 31.

The long weighted arms of levers 34 carry friction shoes 38 adapted to engage drum 39 which is part of casing 25.

Flange 36' is provided with perforations 4I) into and through which pins 4| carried by shift collar 42 may be projected into perforations 43 in spider 32 when arms 34 are in their inner, no-speed, position.

Reverse movement of carrier may be prevented by one-way clutch 50 interposed between the carrier and drum 5| which may be held against rotation by manually controlled brake 52.

Operation is as follows: It will be readily understood that the means by which power is applied to impeller I0, whether by direct connection to a prime mover, or .through a driving train including a manually controlled clutch, an automatic speed-sensitiveclutch, or a for convenience, will be designated first runner and second runner I2.

The epicyclic gearing comprises three coaxial sun gears I3, I4, I5, carried 4respectively by a shaft I6, sleeve; shaft II, and sleeve shaft I6.' Inf'- terposed between shaft I6 and impeller I0 is a one-way clutch I9 permitting the impeller to act fluid coupling, etc., is immaterial, so far asv the operation and control of concerned.

First -speedy fmvard--Drum, 5| is held against rotation by brake 52, pins 4| are withdrawn from perforations v43, and clutch 2| is in engagement with runner I2 to connect runner I2 with sleeve Iland gear I5. Well known connected levers for my present apparatus is simultaneously properly controlling brake 52,

'I clutch 2|, and collar 42 would be immediately .apparent to any one skilled in this art.

only forwardly on shaft I6 and sun. gear I3.l

Interposed between sleeve shaft I 'I and the first runner II is a one-way clutch 20 permitting said runner to act only forwardly on' shaft lI8 and sun gear- I4. The second runner I2 is connected to sleeve shaft I3 so as to drive saidsun` gear forwardly by the clutch 2| splined on sleeve shaft I3 and axoially shiftable `into engagement with runner I2 to holdshaft I8 and gearl I5 stationary.

Coaxial with the su'n gears is a gear carrier 25 carrying a planetary gearunit comprising gears 26, 2l, 28 meshing respectively with the sun gears I3, I4, I5 and also including a planetary gear 29 rotating and revolving with gears 26, 21, 28.

l r into engagement with the stationaryteeth 22 so as Upon'- rotation of impeller |0`, shaft I6 is engaged yby one-way clutch I9 .to rotate sun gear I3 and the flow of power is thence through gears 26, 29, 30, sleeve 3|, spider 32, levers 34, pins 35, arms 36, ange 36', to they output shaft 31, carrier 25 being held against reverse rotation, by one-way clutch 50. Impeller I0 being in forward rotation, moves runners I and I2 forwardly, runner II faster than runner I2, and sleeve I8 under- :uns runner II by reason of one-way clutch' 20.

Gear 29 meshes with a gear 30 coaxial with the sun gears and carried by sleeve shaft 3| which also carries spider 32 having radially projecting fingers 33 engaging the 'short arms of weighted speed-sensitive levers 34 in opposition to centrifugal forces acting on said levers. Levers 34 are pivoted lonstuds I6 which are parallel' with the Under these conditions the reverse action of spider 32 on levers 34 prevents them'from respondingto low-speed centrifugal forces imposed on them so that the clutch .between carrier 25 and the output shaft remains inactive.

Second speed forward-As the differential between input and output torques decreases by at' tainment of increased speed of the load on the output shaft, or by increased speed ofv impeller III, runner vII catches lup with sleeve I 1, whereupon the iow of power is from runner I I through A clutch 20, sleeve I1, gears I4, 21, 29. and thence to the tail shaft as described above, and the transmission is operating in second speed.

Third speed forward-Upon further decrease of the differential between input and load torques, or increased speed of impeller I0, runner I2 begins to exert a driving force on gear I5 and the flow of power is through gears 28, 29, 30 and thence to the output shaft as described above, and the device is operating in third speed..

Fourth 'speed-direct drive- Upon further decrease of the differential between input and load torques, levers 34 respond to the centrifugal forcesimposed on them and the shoes 38 are activated to couple carrier with the output shaft, the epicyclic.- gear .acting as a unit to directly couple the input and output shafts.

It should be noted, however, that the input forces continue to be imposed on the several gears of the unit through the impeller and runner elements of the fluid coupling so that, upon sumcient increase of the differential between input and load torques, the apparatus will automati' cally function successfully in third, second, or rst speed in accordance with variations in that differential.

When a speed-sensitive clutch or fluid coupling -is incorporated in the driving train for impeller III, the motor cannot be stalled by any imposed load,l but the motor cannot be rotated by forward movement of the vehicle. Where a manually controlled clutch is incorporated in the driving train for impeller IIJ, the above conditions are reversed.

For reverse drve.-Drum .5I is released and clutch 2l is shifted. into engagement with teeth 22 tov hold gear I5 against rotation, and pins 4l are projected' into perforations 43 to prevent shoes 38 from being thrown into engagement with drum 29 because of the reverse rotation of spider 32. The ow of power is thence through I0, I9, I6, I3, 25, 28 rolling reversely on stationary gear I5, causing carrier 25 to rotate reversely-thereby causing gear 29 to rotate gear 30 and the output shaft reversely. Gear 29 rotates forwardly about its own axis but also revolves reversely about the axis of the casing 25 and, as gear 29 is smaller than gear 28 and gear 30 larger than gear I5,.the resultant is a low-speed reverse rotation of gear 30 and a corresponding reverse rotation of the output shaft.

Referring now to Figs. 3 and 4. The short arm of each lever 34 (34 of Fig. 1) is provided with a tooth 34 which engages in a notch 60 in an equalizer ring 6I acted on by a series of springs 62, anchored on pins 35 to normally retract shoes 38 from drum 39. Ring 6I takes the place of spider 32 of the construction shown in Fig. 1 and is keyed. to gear 30. This construction insures uniformity and initial bias of the arms 34 toward their inner positions.

It is not essential, when locking sleeve shaft I1 against rotation, as by shifting 2| into engagement with 22, to release runner I2 because reverse rotation of the output shaft may be attained even though runner I2 be held against rotation. A However, if runner I2 is held against rotation it might operate as a dragon runner I I and impeller I0 tending to decrease the attainable reverse speed of the output shaft.

The construction shown in Fig. 5, differs from that shown in Fig. 1 only in the means provided forapplying torque to the several sun gears.

In this construction, power is delivered to element 6o which carries a plurality of speed-sens'itive shoes 6I each biased against centrifugal response by a spring 62 and arranged', when sufficiently displaced by centrifugal action due to speed of element 60, to engage and rotate drum 63 carried by impeller 64 of a fluid coupling. lnterposed between element 60 and shaft I6 is one- 'way clutch 65 by which shaft I6 may be rotated forwardly, and interposed between impeller tl and sleeve shaft I'I is a one-way clutch 65 by which shaft i1 may be rotated forwardly,

The runner 61 of the'iiuid coupling, associated with impeller 64 may be locked to sleeve shaft I8 by clutch 2| as in the other construction.

- 'I claim as my invention:

1. The combination with an epicyclic speedchange gearing comprising, as coaxial elements, a first sun gear, a second sun gear, a third sun gear, an output gear, a planetary-gear carrier, said several gears increased in size in the order named, and an output shaft, a planetary-gear unit having relatively fixed gear elements meshing respectively with said coaxial gears, controllable means for preventing reverse rotation of the planetary-gear carrier, and a speed-sensitive clutch between the output gear and output shaft, of inputmeans comprising a primary input element, a one-way clutch interposed between said primary input element and the first sun gear, a secondary input element driving power from the `primary input element, a one-way clutch interposed between the secondary input element and the second sun gear, a tertiary input element driving power from the secondary input element, and controllable means for blocking rotation of the third sun gear, the secondary and tertiary input elements being so associated as to be relatively rotatable at all times.

2.- The combination with an epicyclicspeedchange gearing comprising, ascoaxial elements, a first sun gear, a 'second sun gear, a third sun gear, an output gear, a planetary-gear carrier, and an output shaft, a planetary-*gear unit having relatively fixed gear elements meshing respectively with said coaxial gears, controllable `the third sun gear, the secondary and tertiary input elements being so associated as to be relativelyrotatable at all times.

LEE OLDFIELD.

t f ERHEICAIE 0F CORRECTION. Patent No. 2,578,577. n June 19, 1915.

of lthe above numbered patent requiring correctiones follrs: Page. 2, second column, lines 56 and [5.0, claim l, for "driving" read --deriving--g and that the said Letters Patent shold be read with this correction therein ,Leslie Frazerv (Seal) y First Assistant Cmmissioner of Patents. 

